<template>
  <view>
    <view class="search-box">
      <my-search :bgcolor="'#C00000'" :radius="15" @click="gotoSearch"></my-search>
    </view>
    <view class="scroll-view-container">
      <!-- 左侧的滚动视图区域 -->
      <scroll-view class="left-scroll-view" :style="{height:wh+'px'}" scroll-y>
        <block v-for="(item, i) in cateList" :key="i">
          <view :class="['left-scroll-view-item', i === active ? 'active' : '']" @click="activeChange(i)">
            {{item.cat_name}}
          </view>
        </block>
      </scroll-view>
      <!-- 右侧的滚动视图 -->
      <scroll-view class="right-scroll-view" :style="{height:wh+'px'}" scroll-y :scroll-top="scollTop">
        <view class="right-scroll-view-item active"></view>
        <view v-for="(item2,i2) in cateLevel2" :key="i2" class="cate-lv2">
          <scroll-view scroll-y="true" class="right-scroll-view" :style="{height: wh+px}">
            <view class="cate-lv2-title">
              / {{item2.cat_name}} /
            </view>
            <!-- 动态渲染三级分类的列表数据 -->
            <view class="cate-lv3-list">
              <!-- 三级分类Item 项 -->
              <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
                <!-- 图片 -->
                <image :src="item3.cat_icon" mode=""></image>
                <!-- 文本 -->
                <text>{{item3.cat_name}}</text>
              </view>
            </view>
          </scroll-view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  import badgeMix from '@/mixins/tabbar-badge.js'
  export default {
    data() {
      return {
        //窗口可用高度 = 屏幕高度 - navigationBar 高度 - tabBar 高度
        wh: 0,
        cateList: [],
        active: 0,
        cateLevel2: [],
        scollTop: 0
      }
    },
    onLoad() {
      //获取系统信息
      const sysInfo = uni.getSystemInfoSync()
      //sysInfo.windowHeight 为屏幕高度 - navigationBar 高度 - tabBar 高度
      //50 为搜索框的高度
      this.wh = sysInfo.windowHeight - 50

      this.getCateList()
    },
    methods: {
      async getCateList() {
        const {
          data: res
        } = await uni.$http.get('/api/public/v1/categories')
        if (res.meta.status !== 200) return uni.$showMsg()
        this.cateList = res.message
        this.cateLevel2 = res.message[0].children
      },
      activeChange(i) {
        this.active = i
        this.cateLevel2 = this.cateList[i].children
        this.scollTop = this.scollTop ? 0 : 1
      },
      gotoGoodsList(item3) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
        })
      },
      gotoSearch() {
        uni.navigateTo({
          url: '/subpkg/search/search'
        })
      }
    },
    mixins: [badgeMix]
  }
</script>

<style lang="scss" scoped>
  .scroll-view-container {
    display: flex;

    .left-scroll-view {
      width: 120px;

      .left-scroll-view-item {
        line-height: 60px;
        background-color: #f7f7f7;
        text-align: center;
        font-size: 12px;

        //激活项的样式
        &.active {
          background-color: #fff;
          position: relative;

          //渲染激活想左侧的红色指示边线
          &::before {
            content: '';
            display: block;
            width: 3px;
            height: 30px;
            background-color: #c00000;
            position: absolute;
            left: 0;
            top: 50%;
            transform: translateY(-50%);
          }
        }
      }
    }

    .cate-lv2-title {
      font-size: 12px;
      font-weight: bold;
      text-align: center;
      padding: 15px 0;
    }

    .cate-lv3-list {
      display: flex;
      flex-wrap: wrap;

      .cate-lv3-item {
        width: 33.3%;
        margin-bottom: 10px;
        display: flex;
        flex-direction: column;
        align-items: center;

        image {
          width: 60px;
          height: 60px;
        }

        text {
          font-size: 12px;
        }
      }
    }
  }
</style>